y2038: add __kernel_old_timespec and __kernel_old_time_t

The 'struct timespec' definition can no longer be part of the uapi headers
because it conflicts with a a now incompatible libc definition. Also,
we really want to remove it in order to prevent new uses from creeping in.

The same namespace conflict exists with time_t, which should also be
removed. __kernel_time_t could be used safely, but adding 'old' in the
name makes it clearer that this should not be used for new interfaces.

Add a replacement __kernel_old_timespec structure and __kernel_old_time_t
along the lines of __kernel_old_timeval.
Acked-by: Deepa Dinamani <deepa.kernel@gmail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

include/uapi/asm-generic/posix_types.h

@@ -86,6 +86,7 @@ typedef struct {
  */
 typedef __kernel_long_t	__kernel_off_t;
 typedef long long	__kernel_loff_t;
+typedef __kernel_long_t	__kernel_old_time_t;
 typedef __kernel_long_t	__kernel_time_t;
 typedef long long __kernel_time64_t;
 typedef __kernel_long_t	__kernel_clock_t;

include/uapi/linux/time_types.h

@@ -28,6 +28,11 @@ struct __kernel_old_timeval {
 };
 #endif
 
+struct __kernel_old_timespec {
+	__kernel_time_t	tv_sec;			/* seconds */
+	long		tv_nsec;		/* nanoseconds */
+};
+
 struct __kernel_sock_timeval {
 	__s64 tv_sec;
 	__s64 tv_usec;